Many schemes have been proposed to limit the output current of transistor amplifiers. Such circuits usually involve a current sensing resistor in the current circuit and some sort of amlifier-control circuit to limit the current when it rises to some threshold level. In the typical prior art circuits the sensing resistor must generate at least one emitter-base diode voltage (V.sub.EB) to render the subsequent amplifier control circuit active. In high voltage circuits this is no problem because the typical 0.6 volt V.sub.EB is not a very great percentage of the applied voltage. However in battery operated devices it is desirable to operate at low voltage, commonly in the 3-volt range. Here 0.6 volt is an appreciable fraction. In addition since battery voltage falls with use, it is desirable to be able to operate a nominal 3-volt circuit at perhaps down to 2 volts where 0.6 volt represents 30%. Accordingly it would be desirable to employ a current limiter that needs substantially less than a V.sub.BE for operation.